Apparatus for treating sheet materials with a liquid



July 11, 1967 J CHEN ET AL 3,330,196

APPARATUS FOR TREATING SHEET MATERIALS WITH A LIQUID Filed May 17, .1965

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INVENTQRS W ATTORNEYS United States Patent M 3,330,196 APPARATUS FOR TREATING SHEET MATERIALS WITH A LIQUID Richard J. Chen, Brockton, and Nicholas Gold, Arlington, Mass., assignors to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware Filed May 17, 1965, Ser. No. 456,423 7 Claims. (CI. 95-89) This invention relates to apparatus for treating sheets with a liquid and, more particularly, to apparatus for applying a non-viscous liquid agent to a side of each of a succession of sheets.

A number of processes, particularly photographic processes, are eifected by applying an accurately predetermined quantity of a liquid-processing agent to one side of each of a succession of sheets. For example, in the process and apparatus disclosed in copending U.S. application, Ser. No. 456,422, filed May 17, 1964, in the name of Edwin H. Land et -al., entitled Photographic Process and Apparatus for Producing Photographic Images, a succession of photosensitive sheets are each treated with a predetermined quantity of a liquid-processing agent applied to one side thereof. The liquid agent employedin such processes is substantially non-viscous, e.g., may have the viscosity of water, and is usually highly corrosive, subject to rapid deterioration when exposed to the atmosphere, and is subject to contamination by the residue of the liquid. An object ofthe invention is to provide novel and improved apparatus for applying a liquid-processing agent .of the type described to one side of each of a succession of sheets while minimizing exposure of the liquid to the atmosphere and preventing contamination of the liquid applied to each sheet by residue of the liquid remaining after application thereof to a preceding sheet.

Other objects of the invention will in part be obvious and-will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which'are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing wherein:

I FIGURE 1 is an elevational, sectional view illustrating apparatus embodying the invention;

FIG. 2 is a fragmentary, sectional view similar to FIG URE 1 illustrating the operation of the apparatus;

FIG. 3 is a fragmentary, elevational view of a component of the apparatus; FIG. 4 is a fragmentary, sectional view taken substantially along the line 4-4 of FIG. 1; and FIG. 5 is a view similar to FIG. 2 illustrating another embodiment of the apparatus. The invention is illustrated in the drawing embodie in photographic apparatus of the type shown and described in the aforementioned application and including means for applying a liquid-processing agent including, I for example, a developer to one side of each of a succession 'of sheets permitting a predetermined quantity of the liquid to be absorbed into each sheet and then removing excess liquid from the sheet by advancing the sheet between a pair of wringer rolls. The apparatus is constructed to apply the liquid to one side of each sheet without contacting the opposite side of the sheet and to avoid waste and contamination of the processing liquid.

T he processing liquid is applied to the sheets by an applicator device comprising a generallycylindrical appliice cator roll10 mounted for rotation about an axis disposed in a generally horizontal plane. The applicator roll includes a smooth outer peripheral surface and is formed of a rigid material which is impervious to and unaffected by the liquid-processing agent. Suitable materials for this purpose include metals, ceramics and organic plastics, the particular choice of materials being dependent to a large extent on their compatibility with the processing liquid to be applied.

Applicator roll 10 is mounted with at least the lower portion of its periphery disposed within an upper recess or cavity 12 formed in a member 14 and having a generally V-shaped cross section with longitudinal side walls inclined inwardly toward the center of the cavity. Roll 10 is mounted for rotation with the peripheral surface thereof spaced from the side walls of the cavity by distances slightly in excess of the thickness of the layer of liquid to be transferred from the applicator roll to the sheets. This spacing is kept to a minimum in order to reduce the area of the surface of the liquid exposed to the atmosphere during coating operations, and utilize as much as possible of the liquid in the cavity.

Member 14 is formed with a lower recess or cavity 16 opening into the central portion of upper recess 12. The upper recess is at least equal in length to roll 10 whereas the lower recess or cavity may be slightly shorter, is substantially rectangular in cross section and is symmetrically oriented with respect to the axis of rotation of the applicator roll. Mounted within the upper and lower cavities is a closure member or valve 18 having an upper flanged section located within the upper cavity and including lips 20 for engaging the upper surfaces of the inclined walls of cavity 12 around the periphery of lower cavity 16 for separating the two cavities and preventing liquid in the upper cavity from flowing into the lower cavity in the closed position of closure member 18 shown in FIGURE 1. Valve 18 includes a lower section disposed within lower cavity 16 mounted on a first shaft 22 extending axially from the end of a second shaft 24. Second shaft 24 extends through an opening in the side of member 14 into lower cavity 16 and is rotatable about its axis within the opening for moving shaft 22 mounted eccentrically with respect to the axis of shaft 24 and engaged in a horizontal slot 26 in the lower portion of valve 18 so as to move valve 18 between the closed position shown in FIGURE 1 and a raised or open position shown in FIG. 2.

In the operation of the apparatus, shaft 24 is rotated to lower valve 18 into its closed position and a quantity of liquid 28 slightly in excess of that to be applied to a sheet is introduced into upper cavity 12 above closure member 18 and applicator roll 10 is rotated to apply a layer of liquid to the peripheral surface of the roll and carry the liquid upwardly into contact with a sheet 30 which is moved substantially in a plane relative to and in contact with an upper axial portion of the periphery of the roll. The liquid is, of course, contained in a suitable airtight container prior to use and is dispensed into the cavity through a conventional valve and conduit (not shown).

Means are provided for supporting and moving a sheet against the applicator roll to transfer liquid 28 from the roll to the sheet. In the form shown, these means comprise a generally cylindrical backing roll 32 mounted for rotation about an axis located above and substantially parallel with the axis of rotation of the applicator roll. Means are provided for rotating backing roll 32 in the same direction as the applicator roll so as to move sheets 30 tangent to the applicator roll in a direction opposite to the direction of movement of the peripheral surface of the applicator roll in contact with the sheets. It is important to minimize the area of contact between the backing and applicator rolls during periods when the rolls are rotated and there is no sheet engaged therebetween because the adjacent portions of the roll peripheries are moved in opposite directions and liquid may be transferred from the applicator roll to the backing roll and thence to the upper surfaces of the sheets. In order to limit friction between the applicator and backing rolls and prevent trans fer of the liquid to the upper surfaces of the sheets, the backing roll is provided with a plurality of axially spaced cylindrical collars 34 each having a sharpened outer cylindrical edge for engaging sheets 30 and the applicator roll and reducing the area of contact between collars 34 and the applicator roll. Of course, friction between the applicator roll and sheets poses no problems because the sheets may not actually contact the roll surface because of the layer of liquid between the sheets and the roll.

The applicator device of the invention is constructed so that only a minimum of excess processing liquid need be introduced into cavity 12 for each sheet and because the liquid deteriorates upon exposure to the atmosphere and is contaminated by its own residue, the device also includes means for removing excess liquid from the cavity and the applicator roll following coating of each sheet. These means include valve 18 which is raised to its open position shown in FIG. 2 so that the liquid within the upper cavity flows into the lower cavity from whence it is drawn through conduit 35 by means for reducing the pressure in conduit 35 and lower cavity 16 below ambient pressure. The upper surface of closure member 18 is formed with cylindrical radius substantially equal to the radius of the applicator roll so that in the open position of the closure member, the upper surface thereof is disposed in juxtaposition with the peripheral surface of the roll thereby expelling the liquid from between the roll and the closure member. Valve 18 is moved upwardly into its open position in engagement with applicator roll 10 immediately after application of the liquid to a sheet and the roll is rotated through at least one additional revolution in contact with valve 18 in order to remove any remaining liquid from the surface of the applicator roll to prevent the liquid from drying and forming a residue on the applicator roll. To facilitate rotation of the applicator roll against valve 18, at least the upper portion thereof which contacts the roll may be formed of a material such as polytetrafiuoroethylene having a relatively high coeflicient of friction, good wear characteristics and characterized by inertness to many liquid reagents, particularly those used in photography.

An alternate embodiment of the applicator device is illustrated in FIG. 5 of the drawings and includes an applicator roll and member 14 provided with an upper cavity 12 and a lower cavity 16 substantially as shown and described with reference to FIGS. 1 and 2. The basic difference resides in the construction of the closure memher which is provided on its upper side with a wiper member 36 mounted on the upper surface of the closure member and curved in the region of the closure member to conform substantially to the peripheral surface of applicator roll 10. A longitudinal edge portion 38 of wiper member 36 is curved toward and into engagement with applicator roll 10 and functions as a squeegee for removing processing liquid from the side of the applicator roll moving downwardly into recess 12. Wiper member 36 is preferably formed of a resilient material having a relatively low coefiicient of friction, polytetrafluoroethylene being particularly suited to this purpose. Channels 40 may be provided in the wall of the cavity underlying edge portion 38 for conducting liquid removed by the wiper member from the applicator roll beneath the wiper member into cavity 16.

The applicator device of the invention is illustrated as embodied in apparatus for applying excess liquid to a sheet, allowing the liquid to be absorbed into the sheet and then removing the excess liquid from the sheet after a predetermined portion of the liquid has been absorbed into the sheet. The means for removing excess liquid from the sheets are shown as comprising a pair of wringer rolls 42 and 44 mounted in juxtaposition a predetermined distance from the applicator roll. Wires 46 are provided above and beneath the path of movement of sheets 30 for guiding the sheets from the applicator roll between the Wringer rolls. An endless perforated web is engaged around wringer roll 42 so that liquid removed from each sheet 30 and collected at the nip of the wringer rolls will enter and become entrained in the perforations of web 48. The web passes between two facing chambers 50 and 52 and means are provided for introducing air under pressure into one chamber to pass the air through the perforations in the web and expel the liquid into the other chamber from whence it is withdrawn by the same means coupled with conduit 35 for withdrawing liquid from lower cavity 16.

The applicator device described is constructed to transfer substantially all of a predetermined quantity of liquid by way of an applicator roll from a recess to the surface of a sheet moved tangent to and in contact with the applicator roll; and includes means for removing any excess liquid from the recess and the applicator roll so that the liquid is not applied to the next succeeding sheet and is not given opportunity to evaporate and form a deleterious residue on either the roll or within the cavity,

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Apparatus for applying to a succession of sheets, a liquid agent subject to deterioration upon exposure to the atmosphere, said apparatus comprising, in combination:

means providing a cavity having inwardly sloping walls;

a generally cylindrical roll mounted for rotation within said cavity;

an opening in the bottom of said cavity;

a closure member for said opening mounted within said cavity beneath said roll for movement between open and closed positions;

said closure member including a portion for engaging a longitudinal section of said roll extending substantially from end to end thereof when said closure member is in said open position; and

means for introducing said liquid agent into said cavity above said closure member;

means for rotating said roll in contact with a sheet to apply said liquid thereto and in contact with said portion of said closure member to remove said liquid therefrom.

2. The apparatus of claim 1 wherein said opening in said cavity is at least equal in length to said roll.

3. The apparatus of claim 2 wherein said closure member includes an upper concave cylindrical surface having a diameter substantially equal to the diameter of said roll.

4. Apparatus as defined in claim 1 including means for withdrawing said liquid from said cavity through said opening.

5. Photographic apparatus as defined in claim 1 including means for supporting a sheet against the upper portion of said peripheral surface of said roll and moving said sheet relative to said roll, comprising a second roll mounted above said cylindrical roll for rotation about an axis substantially parallel with said axis of said cylindrical roll; and a plurality of axially spaced rings engaged around said second roll, each of said rings having a sharpened cylindrical outer edge for contacting said sheet and said cylindrical roll.

6. Apparatus for applying to a succession of sheets, a liquid agent subject to deterioration upon exposure to the atmosphere, said apparatus comprising, in combination:

container means formed with a cavity having inwardly sloping walls;

a cylindrical roll mounted for rotation about its axis 5 within said cavity with the peripheral surface of said roll located adjacent said walls;

an opening in the bottom of said cavity at least equal in length to said roll;

a closure member at least equal in length to said opening and including an upper concave cylindrical surface having a diameter substantially equal to the diameter of said roll;

said closure member being mounted Within said cavity beneath said roll for movement between a closed position at which said closure member engages said walls at the edges of said opening closing the latter and an open position at which said cylindrical surface is in contact with said roll and said member is spaced from said walls;

means for moving said closure member between said open and closed positions;

means for introducing said liquid agent into said cavity above said closure member;

means for rotating said roll to transfer said liquid from said cavity to a sheet supported against said roll, and

means are formed with a second cavity beneath the firstmentioned cavity;

said opening communicates with said second cavity;

and said means for withdrawing said liquid are coupled with said second cavity for withdrawing said liquid therefrom.

References Cited UNITED STATES PATENTS 1,198,655 9/1916 Perkins 118261 1,891,722 12/1932 Murck 95-89 2,289,798 7/1942 Nadeau et a1.

3,195,430 7/1965 Young 951.7

NORTON ANSHER, Primary Examiner.

FRED L. BRAUN, Assistant Examiner. 

1. APPARATUS FOR APPLYING TO A SUCCESSION OF SHEETS, A LIQUID AGENT SUBJECT TO DETERIORATION UPON EXPOSURE TO THE ATMOSPHERE, SAID APPARATUS COMPRISING, IN COMBINATION: MEANS PROVIDING A CAVITY HAVING INWARDLY SLOPING WALLS; A GENERALLY CYLINDRICAL ROLL MOUNTED FOR ROTATION WHEREIN SAID CAVITY; AN OPENING IN THE BOTTOM OF SAID CAVITY; A CLOSURE MEMBER FOR SAID OPENING MOUNTED WITHIN SAID CAVITY BENEATH SAID ROLL FOR MOVEMENT BETWEEN OPEN AND CLOSED POSITIONS; SAID CLOSURE MEMBER INCLUDING A PORTION FOR ENGAGING A LONGITUDINAL SECTION OF SAID ROLL EXTENDING SUBSTANTIALLY FROM END TO END THEREOF WHEN SAID CLOSURE MEMBER IS IN SAID OPEN POSITION; AND MEANS FOR INTRODUCING SAID LIQUID AGENT INTO SAID CAVITY ABOVE SAID CLOSURE MEMBER; MEANS FOR ROTATING SAID ROLL IN CONTACT WITH A SHEET TO APPLY SAID LIQUID THERETO AND IN CONTACT WITH SAID PORTION OF SAID CLOSURE MEMBER TO REMOVE SAID LIQUID THEREFROM. 